For example, in manufacturing of an interior material for automobiles formed by bonding a substrate and a surface material together, the substrate and the surface material are pressure-bonded and joined together between an upper and a lower die and, at the same time, the surface material is cut by a heat cutting blade (for example, see numeral 6 in the figure of Patent Document 1). Such a heat cutting blade is a kind of linear cutter and, as shown in FIG. 4, includes: a linear body 14a cut in advance into a predetermined length in accordance with a usage situation or the like of the heat cutting blade 14 like the shape, the size, or the like of an object material to be cut; and a cutting edge 14b formed at least at one edge of the body 14a. The heat cutting blade 14 is formed from an electrically conductive linear-shaped material such as nickel chrome alloy and stainless steel. Then, when the heat cutting blade 14 is energized, the heat cutting blade 14 is heated so that the object material can be melted and cut or, alternatively, pressure-bonded and joined.
Meanwhile, in general, such a heat cutting blade (a linear cutter) 14 is fabricated by the process steps shown in FIG. 5. Here, FIGS. 5(a), 5(b), and 5(c) schematically show the manufacturing process for the linear cutter. Then, FIGS. 5(d) and 5(e) are enlarged views each showing the cross section of each wire rod corresponding to FIG. 5(a) or 5(b). FIG. 5(f) is a sectional view of a completed linear cutter.
First, a metal wire rod (a round wire 10) is prepared that has been cut in advance into a predetermined length in accordance with the usage situation or the like of the heat cutting blade 14. Then, the round wire 10 is set between dies 11a and 11b of a pressing machine (see FIGS. 5(a) and 5(d)). Then, the dies 11a and 11b of the pressing machine are closed together so that the round wire 10 is pressed and thereby a body 14a having a flat wire shape of pre-set thickness is formed (see FIGS. 5(b) and 5(e)). After that, one edge of the body 14a is grinded from both sides by using a whetstone 13 so that a cutting edge 14b is formed (see FIG. 5 (c)). At last, a finishing process such as deburring of the blade edge of the cutting edge 14b is performed so that the heat cutting blade 14 is completed (FIGS. 4 and 5 (f)).
As such, in the conventional manufacturing process for a linear cutter, a plurality of process steps are necessary like cutting of the round wire, setting to the pressing machine, pressing, extraction from the pressing machine, setting to the grinder, grinding, extraction from the grinder, and finishing. Thus, there has been a problem of long processing time and high cost.
Further, the processing is performed by using a round wire having been cut in advance into a predetermined length. Thus, when an order of a linear cutter having a special length exceeding a standard length is received, the processing need be started from the cutting of a round wire and hence a problem is caused that much time is taken from order receipt to shipment. Further, in such a case, when the length of an ordered linear cutter exceeds the capability of the owned pressing machine, a problem is also caused that the order cannot be accepted or, alternatively, a new pressing machine or new dies need be purchased.
Further, plural kinds of dies and pressing machines corresponding to the lengths of the round wires need be prepared and hence a problem of high facility cost is also caused.